How to Install a 3000 Watt Inverter

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A 3000 watt inverter can run a refrigerator, air conditioner, other appliances, power tools and large motors. This system can be installed in a house, RV, truck and other grid / off grid solar power systems as well. This guide explains step by step how it is done.

There are 5 basic steps to installing a 3000 watt inverter.

Step 1. Plug the remote on/off switch into the inverter.
Step 2.
Mount the inverter.
Step 3.
Connect the inverter chassis to a system or vehicle chassis DC grounding point
Step 4.
Plug the AC output if connecting to preexisting AC power.
Step 5.
Plug in the DC cables.

Before Installation: Read the Following

The following is a general overview of how to install inverters regardless of size . Before you proceed with the installation, please read and follow these safety warnings and precautions.

Inverter Safety Instructions

  • Follow the instructions carefully.
  • Do not disassemble the inverter. Doing so will void the warranty and may render the device inoperable.
  • Do not install the inverter if it shows signs of damage or if it has been dropped.
  • Use only the manufacturer recommended wire sizes.
  • Use quality wiring.
  • Make sure all the items are in the box. Remove all the contents and make sure nothing is missing.
  • Do not block the ventilation opening.
  • Some inverters work with 12V and 24V batteries, but others are compatible with only one voltage type. Use only the battery voltage the inverter is designed for.
  • Do not install the inverter where it will be exposed to rain, snow, extreme heat, extreme cold or water.
  • Always turn off and disconnect the DC power before doing any inverter maintenance or troubleshooting.
  • Inverters contain materials that can generates arcs so exercise caution.

Battery Safety Instructions

  • Read the instructions that came with your battery.
  • Prepare, install and use the battery as indicated by the manufacturer in the instruction manual.
  • If you are using lead acid batteries, ensure they are properly maintained. These batteries can explode if not properly taken care of.
  • Ensure the battery bank is installed in a well ventilated area.
  • If one of the batteries has to be removed, turn off the system. Disconnect all cables and ay peripherals or accessories.
  • Do not place any metal object near the battery. Avoid dropping metallic objects near the system as it could be an explosion hazard.
  • Do not smoke near the battery bank, inverter or any part of your solar system.
  • Do not install the batteries anywhere near flammable materials.

Personal Safety Instructions

  • Wear long sleeved clothing when working near lead acid batteries.
  • If lead acid gets onto your clothing, remove the clothing and wash with water right away.
  • Wear goggles or other types of eye protection.
  • If you get battery acid on any part of your body, wash with cold water and seek medical attention immediately.
  • Do not wipe or touch your eyes when working with batteries or inverters.
  • Have water nearby in case battery acid gets on your skin.
  • Do not wear watches, bracelets, or any metal objects when installing an inverter or battery.

Inverter Cable Size Requirements

There are many types of cables used in solar system installations and inverters are no different. The cables used has a huge effect on performance, safety and reliability.

  • Use the shortest DC cable and largest gauge.
  • The cable between the battery and inverter must be no more than feet long.
  • Use copper wires. Avoid aluminum because it generates more resistance.
  • As per the NEC, the smallest cable size allowable is #4/0 AWG 75C.
  • The smallest DC cable that you can use is #2/0 AWG.
  • The recommended ground chassis wire size is #8 AWG.
  • For connections to the hardwire terminal block AC output, use jacketed #10 AWG.

Required Tools

  • Philips screwdriver
  • Hex key screwdriver
  • Cable crimping tool
  • Wire stripper
  • 1/2 inch wrench for the ground stud and cable terminal

Required Materials

This is a general list. Your system may require other materials, so check the installation guide.

  • DC circuit breaker, fuse, fuse holder, disconnect switch
  • Terminals and lugs (for connecting the DC cables that are joined to the disconnect switch and fuse holder for the battery
  • 5/16 inch size ring terminals (2x). The size is based on the wire gauge that will connect the DC input terminal and DC cables.
  • DC input cable (copper)
  • Corrosion proof fasteners (4x), size #10 or larger

Install the On/Off Remote Switch

There is a remote switch jack on the inverter, usually at the front. Plug the switch into the jack. When installed you will be able to control the inverter from a distance, usually up to 20 feet. Most 3000 watt inverters have a remote control, but smaller ones may not.

The way these remote control systems work varies per inverter. Refer to the documentation included with your inverter for specific instructions on testing and usage. If your system does not have this feature, proceed to the next step.

Mount the Inverter

Note: this is for a permanent installation

The inverter must be installed in the proper location. Make sure the location you chose adheres to the following guidelines.

  • Do not place the inverter where battery gases might reach it. Prolonged exposure will damage the system and any appliance connected to it.
  • Use short wires. The shorter the wires and cables used, the lower the voltage drop. Short cables also reduce heat buildup.
  • Do not mount the inverter close to any flammable or combustible material.
  • There must be clearance of at least four inches around the inverter. This is necessary for air to flow.
  • Inverters are designed to run under a specified temperature range. Most of them can work between 32 to 105F (0 to 40C). This can vary by manufacturer.
  • The inverter must be installed on a vertical or horizontal surface.

To mount the inverter, follow these steps:

  1. Ensure the on/off switch is set to off.
  2. Choose a suitable location following the guidelines given earlier.
  3. When you have a spot, mark the areas for the mount screw holes.
  4. Drill the four screw holes for mounting.
  5. Use the fasteners to secure the inverter in place.

Connect the Inverter Chassis

Your inverter comes with a stud connector marked “chassis” or something similar. It is usually on the side. Use this stud to link the inverter chassis to the system or the RV or jeep DC grounding point Connecting the inverter chassis to a grounding point is required. A bare 8 AWG copper wire should be connected between the DC grounding point and the inverter chassis lug.

  1. Ensure the inverter remote switch is set to off.
  2. Use the 1/2 inch wrench to loosen the chassis stud.
  3. Fasten the lug to a level of 216-240 in lb. torque. The amount may be different with your inverter.

Plug the AC Output

AC loads can be plugged into the receptacles located in front of the inverter. Most of these systems have a limit of 20A so make sure the output does not exceed that.

  1. If you have not already, disconnect every DC power source from the system.
  2. In a preexisting AC load panel, place an extra circuit breaker or a dedicated AC load panel. The circuit breaker current rating will depend on the load current it will supply. The typical breaker size is 30A, assuming there is a 2500W continuous output and a #10 AWG.
  3. Take out the AC wiring from the panel.
  4. Take out the screws on the AC panel.
  5. Find the terminal block with the Ground, Neutral and Line connectors. These have labels for easy identification.
  6. Strip the line, ground and neutral connectors up to 9 mm / .35 in
  7. Put a strain relief device onto the AC knockout.
  8. Run the line, ground and neutral wiring into the strain relief and AC knockout devices.
  9. Go to the left side of the terminal block. Loosen the screws. In some cases the screws may be lose already. Do not loosen the right side screws.
  10. Place the ground wire in the section marked “ground” connector. Secure the wire. Repeat this step with the neutral and line wires.
  11. Once the AC strain relief has been installed, replace the AC panel and tighten the screws.
  12. The last step is connecting the outgoing AC cables to the AC panel.

Connect the DC Cables

Follow these steps to complete the inverter installation.

  1. If necessary, cut the cables to achieve the required length. Your installation manual will provide additional information on this.
  2. Connect the cables to the connectors. If you are going with compression lugs, use a crimp tool to connect the cables onto the terminals. Be certain that no wire strands are straying. If you have box lugs, connect the lug onto the inverter, then the wire and tighten with screws.
  3. Run the DC cables to the inverter from the battery bank.
  4. Place a fuse and a breaker or disconnect switch between the battery and the inverter. Make certain the disconnect switch or breaker is turned off before installation. It must be installed as near the battery as possible and at the DC circuit positive side.
  5. Plug a connector onto the positive wire on the DC end positive terminal. For the other connector, connect it to the breaker or fuse positive terminal.
  6. Attach a connector on the DC end negative cable on the negative terminal. Get the other end of the cable and attach it to the battery negative terminal. Ensure the cables are tight.
  7. Place the terminal covers on.
  8. Turn the breaker or battery disconnect switch on.
  9. If your system has a battery selector switch, use it to choose a battery bank or battery.
  10. Move the inverter switch position to on.
  11. Plug an appliance into the AC receptacle to see if it runs.

Conclusion

The installation instructions provided here are for those who have knowledge of, and are comfortable handling these electrical components. If you have never installed an inverter before, please consult a licensed installer.